solar water heater tubes

solar water heater tubes
1. material tube heavier
2. coating time longer
3. checking equipment imported from Germany


solar water heater tubes
Specification
Structure: Two concentric borosilicate glass tubes
Material: Borosilicate glass 3.3
Outer tube diamete: Φ47/Φ58
Inner tube diameter: Φ37/Φ47
Length: 47-1500mm/1600mm/1800mm;
58-1500mm/1600mm/1800mm/2000mm/2100mm
Coating: single-target
Glass thickness: 1.6mm/1.8mm/2.0mm
Vacuum degree: P<5*10-3Pa
Thermal expansion: 3.3*10-6/°C
Insolation temperature: >200°C
Absorptance: >89%
Emittance: <12%
Heat loss: <0.8W(m2°C)
Maximum strength: 0.8Mpa
Resist cold: -35°C
Resist hail: 25mm/30mm/35mm
Resist wind: 30m/s
Start-up temperature: <=25°C
Lifetime: 15 years